The Northrop JB-1 "Bat" was a United States surface-to-surface cruise missile that was a prototype jet-powered flying wing. The United States Army Air Forces MX-543 program was initiated in September 1942 to use US versions of Frank Whittle's jet engine (US-named General Electric J31). The Northrop Corporation was contracted in late 1943, and only 10 JB-1 airframes were built. A manned version was towed for the 1st flight on "August 27, 1943", [sic] from Rogers Dry Lake; and a glider version was launched from a rocket-propelled sled and crashed in December 1944. An unmanned JB-1 powered by an improvised General Electric B-1 turbojet with a wing span of 28 feet 4 inches (8.64 m) made its 1st flight from Eglin Field's Santa Rosa Island, Florida, on December 7, 1944, and crashed 400 yards from the rail launcher.
JB-10
With the successful USAAF flights of JB-2 pulsejet-powered copies of the V-1 flying bomb, the older JB-1 program was "reoriented towards pulsejet propulsion, and the remaining JB-1s were modified or completed as JB-10 missiles." Only one of the JB-10 variants was completed by the end of the war (with Ford PJ-31-1 pulsejet engine), and 1945 sled launches using 4 Tiny Tim rockets were at Muroc Field and Eglin. In June 1996, the Western Museum of Flight restored the only remaining airframe as a manned JB-1.